The subject matter of the present invention relates to a door joint for motor vehicles.
It has been known that such door joints usually have a fixing element that can be firmly attached to a projecting part of the door-frame and an adjoining tubular element or "draught-tube" which can be deformed in an elastic manner while compressed between the door-frame and the associated door. The fixing element usually has a U-shaped section and a wireframe coated with polyvinylchloride, for example. This element caps a projecting border of the body and, to avoid its accidental disengagement from its bearing (said projecting border), the inner sides of the U-shaped section usually comprising rubber lips are designed to keep this part of the door joint in place. The "draught-tube" is usually made of cellular rubber or similar material and ensures the tightness between the door-frame and the associated door when compressed.
However, it is often preferable to reinforce this tightness and, in order to do so, the use of two adjoining tubular elements simultaneously deformed when the door is closed has been suggested. This well-known system, however, exhibits the disadvantage of requiring a greater effort when closing the door.
The object of the present invention is the elimination of this disadvantage by the suggested door joint made of two tubular elements which are to be gripped between a door-frame and the associated door, offering only low resistance to the closing of the door.
The present invention also suggests a sealing joint of this type, thereby ensuring improved tightness compared with the two tubular element joints of the previous technique.
Considering this, the object of the invention is a door joint for automobile doors comprising a fixing element covering a projecting part of the door-frame and two tubular elements made of a material deformed in an elastic manner. One tubular element is adjoining the other tubular element and the fixing element. These tubular elements are to be interposed between the door-frame and the associated door in its closed position in order to ensure the tightness of the assembly. This door joint is characterized in that the two tubular elements communicate through at least one orifice or a continuous passage. The compression of one of the tubular elements between the door and the door-frame results then in its deformation and in an inflation of the second tubular element between said door and said door-frame.
Preferably, the tubular element to be deformed will be placed between the edge of the door and the associated part of the door-frame while the second tubular element--communicating with the first one through at least one orifice or a continuous slit--will be interposed between the inside surface of the door and the door-frame. The size of this said second element is such that its compression between the door and the door-frame will only occur when said element is expanded due to the pressure of the air forced out from the other tubular element.
In other words, when the first tubular element is compressed between the edge of the door and the associated part of the door-frame, it is deformed and part of the air within is forced out and transferred into the second tubular element through communication orifices or through the continuous passage formed between them, so that said second element may expand and press firmly against the door and the door-frame while ensuring further tightness at this point.
Only one of the two tubular elements will then be directly engaged in the closing of the door and the joint according to the invention will not offer a closing resistance greater than the one offered by the single "draught-tube" joints of the previous technique. On the other hand, because of the inflation of the second tubular element in closed position of the door, the joint according to the invention will ensure reinforced tightness appearing in each of the two tubular elements.
The result is a noticeable improvement of the insulation (soundproofing) of the vehicle due to the two barriers created to oppose the passage of noise, as well as improved water-tightness.